Abstract
Numerous attempts to manipulate/transport liquid drops have been conducted over the past ten years to develop functional surfaces for applications such as biochemical microfluidics, self-cleaning, anti-icing and controlled/enhanced heat transfer surfaces. In this paper, we show a millimetre-sized water drop running/jumping, without any external forces, on an interface between two superhydrophobic surfaces with different degrees of wettability. A systematic study of the effect of wettability contrasts on drop motion was carried out employing well-defined micropatterned surfaces with various pillar densities. Motion of the drop precisely deposited by a machine-controlled drop dosing system (KRÜSS DSA100) was captured and analysed using a visual CCD camera and a custom image processing programme. Right after a drop was gently placed on the interface, the drop moved toward the surface with denser pillars i.e. less hydrophobic. Drop motion was instigated by vertical oscillatory motion. In turn, the oscillation was induced by drop surface deformation caused during deposition. Moreover, we found that the drop velocity increased proportionally to the wettability (or pillar density) contrasts between the surfaces.
Original language | English (US) |
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Pages (from-to) | 2433-2438 |
Number of pages | 6 |
Journal | International Heat Transfer Conference |
Volume | 2018-August |
DOIs | |
State | Published - 2018 |
Externally published | Yes |
Event | 16th International Heat Transfer Conference, IHTC 2018 - Beijing, China Duration: Aug 10 2018 → Aug 15 2018 |
Bibliographical note
Funding Information:This work was supported by the Japanese Society for the Promotion of Science (JSPS) KAKENHI Grant Number 17J05137.
Publisher Copyright:
© 2018 International Heat Transfer Conference. All rights reserved.
Keywords
- Bio and medical applications
- Condensation
- Drop motion
- NEMS/MEMS
- Superhydrophobic surfaces
- Two-phase/Multiphase flow
- Wettability